Hi Rekebeh,
U can use this FM.
CALL FUNCTION 'LTRM_TIME_GAP_CALC' "Calculate time difference between two time stamps
EXPORTING
i_locat = " lloct-locat Site
timestamp1 = " ccupeaka-timestamp Timestamp im Format "JJJJMMTTHHMMSS"
IMPORTING
difference = " i Difference TimeS1 - TimeS2
. " LTRM_TIME_GAP_CALC.